Log the useragent string with quotes for better parsing

host/embedhost/host.go

@@ -72,7 +72,7 @@ func Run(flags *flag.FlagSet, args []string) {
 	http.Handle(servePath, http.StripPrefix(prefix, http.HandlerFunc(
 		func(w http.ResponseWriter, req *http.Request) {
 			fullPath := prefix + req.URL.String()
-			clientName := fmt.Sprintf("%v:%v (useragent: %v)",
+			clientName := fmt.Sprintf("%v:%v (useragent: %q)",
 				req.Header.Get("X-Forwarded-For"), req.Header.Get("X-Forwarded-For-Port"),
 				req.UserAgent())
 			if err := dir.CheckPasswordsFiles(w, req); err != nil {

portal/embedportal/http_proxyserv.go

@@ -305,13 +305,13 @@ func (p *httpProxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		// server seems to return errors for empty URIs so there has to be something
 		// in there. The parsing code is too complex to guess what it could be.
 		http.Error(w, "Empty path requested.", http.StatusBadRequest)
-		log.Printf("%v (useragent: %v) requested an empty req.URL.Path. Raw URI: %v",
+		log.Printf("%v (useragent: %q) requested an empty req.URL.Path. Raw URI: %v",
 			req.RemoteAddr, req.UserAgent(), req.RequestURI)
 		return
 	}
 	fwd := p.selectForwarder(req.Host, req.URL.Path)
 	if fwd == nil {
-		log.Printf("%v (useragent: %v) requested unregistered path: %v%v",
+		log.Printf("%v (useragent: %q) requested unregistered path: %v%v",
 			req.RemoteAddr, req.UserAgent(), req.Host, req.URL.Path)
 		http.NotFound(w, req)
 		return
@@ -361,7 +361,7 @@ func makeChallengeHandler(webRoot string) (http.Handler, error) {
 	}
 	fileServer := http.FileServer(dir)
 	return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
-		log.Printf("%v (useragent: %v) requested %v", req.RemoteAddr, req.UserAgent(), req.URL)
+		log.Printf("%v (useragent: %q) requested %v", req.RemoteAddr, req.UserAgent(), req.URL)
 		fileServer.ServeHTTP(w, req)
 	}), nil
 }